Cassandra basics
- 2. It is a distributed database from Apache . It is highly scalable and designed to manage very large amounts of structured data. High availability with no single point of failure. It is a column-oriented database 2
- 3. Cassandra RDBMS It is used to deal with unstructured data. It is used to deal with structured data. Flexible schema Fixed Schema Relationships are represented using collections. In RDBMS, there are concept of foreign keys, joins etc. It won’t support Join’s It support Join’s 3
- 4. Cassandra is to handle big data workloads across multiple nodes without any single point of failure. Cassandra has peer-to-peer distributed system across its nodes. Data is distributed among all the nodes in a cluster. Advantages and Applicable Area Open Source Peer to peer High Availability & performance.. 4
- 5. The components of Cassandra data model are keyspaces, tables, and columns. Keyspaces - is the outermost container for data in Cassandra. ◦ no default keyspace ◦ Replication is specified at the keyspace level. 5
- 6. CQL does not support aggregation queries like max, min, avg CQL does not support group by, having queries. CQL does not support joins. CQL does not support OR queries. CQL does not support wildcard queries. CQL does not support Union, Intersection queries. Table columns cannot be filtered without creating the index. Greater than (>) and less than (<) query is only supported on clustering column.Cassandra query language is not suitable for analytics purposes because it has so many limitations. 6
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